Trimming device for sewing-machine attachments



May 14, 1929. A. MISTRETTA y 1,713,296

TRIMMING DEVICE FOR SEWING MACHINE ATTACHMENTS.

Filed June 16, 1926 v UNITEDv STATES Patented May 14, 1929. Y.

ANTONIO MISTRETTA, or NEW YORK, N Y, i

TRIMMING DEVICE Fon sEwINe-MAoHiNE ATTACHMENTS'.

Application 'filed `June 16,

This invention lrelates to improvements in ti'iinining attachments for kembroidery sew ing machines especially adapted for use in connection with machines ofthe Bonnaz type for producing appliquev embroidery;

' and its primary object is to provide certain i improvements in the construction v of the trimming device proper, usually forming part of such'attachments in order to improve Aand facilitate its operation; Vsaid trimming Vthe trimming device inrelation to the fabric transversely of the stitching line lwhen change ing the direction of said stitching line.

Other'objects and advantages of the present invention will more fully appearas the description proceeds and will be set forth and claimed inthe appended claims.

The invention relates to improvements in a mechanically operated trimming device which is capable of being turned about its axisin any direction requiredinorder to follow a pattern 0r outline, together with a needle bar capable of such movements under the control of the operator.

"The device is particularly `designed'for cutting out figures fromfabrics parallel to a stitch which follows a certain predetermined outline by virtue of an arrangement whereby the trimming and stitching ai'e effected simultaneously through the cooperation of its various elements.

By appliqufoi" Bonnaz yembroidery is meant that Vhind of work where a' piece or panel of decorative fabric is attached to a base fabric by means of a stitch which follows a certain `predetermined outline representing' some object or flower or animal, or

sonic ,other decorative motif or design.

After the panel or applique work proper has become attached to the base fabric by means of the-stitching, the same is trimmed all around the stitching leaving a relatively f ing the panel 192e; serial No. 116,331. Y

small margin, so thatdue to the difference 'l in the color or texture ofthe materials formpart and the base 'fabric, many novel and artistic ede'cts` mayfbeobtained.

The' workfis generally carried out in two distinct'steps, the first step being that'o'f' pieces together following.

stitchingthe twov the design whichinay have been previously printed on'tliepanel part and thefother step being the trimming of the same which is gen- 'i 7 erally performed by dinary scissors. therefore, which must be exerted in order to keep the widthy of the margin uniform, and thework being largelydependent upon the ability of the lOperator to correctly gauge the width of thermargin allaround, the always allthat could be desir-ed.I l

In my application No.v60,263, above'rehand by meansv ofV or- This trimming operation is necessarily slow, due tothe lcare'.

ferredto, I have described a device comprising a scissordilre implement having a stationary blade 'and a'inovable blade', thel movA able blade being operated by amei'i'iber which is attached to the needle bar and which therefore follows both the aXialfand the angular movements of 'the needle'bar.V Said member transmits the'aXial movements of the needle bar to the movable bladeby means of an articulated connectionk and the angular movements of said'bar to the -cuttingjdevice as a whole so that vthe shearing'line is always set parallel to the stitching'line. I

In operating the said device,- I have foundk it desirableto modifythe same in 'its various details in ordei to obtain better results-f and a more reliable operation, 'and in myk subsequent application No. 89,465,71 have d escribed a similar device by means ofwhich improved results may be obtained due to two improvements introduced in the saine. On'e of these two improvementsconsists in so construct-ing the trimming device that the"0s cillating blade is the innerblade while the stationary blade is the' louter blade, softhat the progress ofthat-part of the worki'which remains attached to the base 'fabric is not hampered; and another'improvement consists in bending the foute'r end of the stationary blade to one side in order to provide a transversal tract,4 offering an eiiicientfsupport for the fabricito becu'tfbythedevice, assisting the feeding action of lthe presser foot.V f 'E The .present inventionmere especially re'- fers to a further improvement in the construction of the stationary blade, the object of said improvement being to obviate certain diificulties which have been encountered in the operation of the device, when certain kinds of cloth are used; -and in describing the device in its present form, 1 will point out in detail the feature which hasI thus been improved by referring to the previous arrangement.

In the annexed drawings* Fig. 1 is a side view in elevation of my trimming attachment as applied to an embroidery machine;

Fig. 2 is a front view in elevation of the same; i

Fig. 3 is a rear view in elevation of the same; Y

Fig. 4 is a side View in elevation of the same with the needle bar in its lower position;

Fig. 5 is a detail plan sectional `view through line 5-5 of Fig. 1;

Fig. 6 is a detail plan through line 6-6 of Fig. 4f;

Fig. 7 is a detail plan through line 7--7 of Fig. 1;

Fig. 8 is a fragmentary plan view of the trimming device proper in operation in its preferred form;

Fi 9 is a detail plan view of the stationary blade used in my previousJ application, No. 89,465, illustrating one of the diiliculties which may hinder its operation when an open mesh fabric is used; and

Fig. 10 is a detail plan view of the trimming device in another modified form, illus tratinganother way of avoiding said didiculty, adapted for use in some special cases.

Referring to Figs. 1 and 2, and 3, 10 designates the needle bar which is represented at the highest point of its reciprocating travel, at which point its lower end 11 still projects beyond the lower end of needle bar casing 12. 13 designates a collar integral with a gear 14, which is an integral part ofthe equipment of the Cornely type of machine; .said gear is rest-rained from axial movement by a retaining forked member 15 inserted in a groove 16, but is free to rotate around needle bar casing 12, upon which said collar is inserted. Said collar therefore made use of for attaching the trimming attachment proper so as to render said attachment free to rotate with the needle bar, about its axis.

The trimming attachment proper consists of a'stationary blade 17 which is carried by a vertical stem 18 depending from collar 13, said stem being secured to said collar by means of a clamping member 19, provided with lateral extensions 20, 21, attached to eollar 13 by means of screws 22.

Clamping member 19 has a longitudinal opening adapted to receive the upper end of stem 18, so that said stem may be adj usted to and from the bed plate of the machine 23 and sectional view sectional vie u'` vpossible to trim only i ployed in producing the can then be clamped in position by means of screws This arrangement therefore renders the device adjustable for different thicknesses of clotlnthe base material upon which the vapplique work is attached by stitching passing between the stationary blade 17 and the bed plate 23.

lhemosfable blade designated by is pivotally mounted at 25 upon the lower end 27 of stem 18, with its cutting edge abutting `against the cutting edge of blade 17 so that the two blades together forni a scissor-like trimming contrivance adapted to trim the applique part Vof trie work quite close to the needle 28 and at a uniform distance from the stitch produced thereby.

The movable blade is caused to oscillate around its pivot by utilizing the reciprocating axial motion of the needle bar. To this end, an upwardly extending member 28 is secured to the lower portion 11 of the needle bar by means of a screw 29 or in any other suitable manner. rlhe upper part 3() of said upwardly extending member is connected to the upper end 31 of the movable blade by means of an articulated connection 32, so that the up and down motion of the needle bar will. cause oscillating motion of said blade 25.

rllhe upwardly extending member 28 has a vertical opening 33 through which passes stem 18, which is thus .maintained in its vertical position. Due to this arrangement it will be observed that the angularmovements of the needleV bar, which are shared by 111cm-,

ber 28 connected thereto, will be transmitted by said member 28 to stem 18 which is guided thereby, causing the collar 13 to lparticipate in said angular n'rovements. In order to insure a sharp cutting action, l provide a spring 3a attached at 35 to the uppervpart 30 of member 28, said spring forcing connection 32'outwardly and maintaining therefore blade 25 in close adherence 'to blade 17; this action bein@ com arable to the side oressure of one blade against the other, which is exerted by hand when using an ordinary pair of scissors. i

The arrangement described Y `causes the cutting device to be operated*simultaneously with the needle bar and also causes the same to follow the angular displacements of the needle bar. Furthermore, by mounting the stationary blade so that the same is detached from the bed plate of the machine and is vertically adjustable in relation thereto, it is one of the fabrics emwork while the other fabric remains intact. This is particularly important in connection. with appliqu work since, as stated, only the appliqu or panel part should be trimmed while the base material should be left untouched.

The material is fed to the needle bar by means of a presser foot 36, associated with the needle bar and movable angularly there-V with, said presser foot movinginwardly eac-h time a stitch is produced in order to feed the fabricfor the next stitch. i

In Fig. 4 where the deviceisshown. in operation, Vapplied to the production. of appliqu work, it will `be observed-that the presser foot is shownin its inward position afterithe feeding action, its original' position j being shown in Fig. l where said foot isco-axial l0V angle to the direction of the' stitching at the i point where the stitching takes place. 2oy the stationary blade is parallell tothe upper It will be observed that the lower edge of surface of the bed plate ofthe machine, in order to providea suitable adJustable clean ance space for the fabric passing there-r through. Itwill alsowbe observed that the stationary blade is very narrow and elongated in form, so that theclothis only slightly raised by the insertion of lsaid stationary blade between the base material and the panel material. v V- y It will furthermore be'observed that the of the fabricwhich iscut and which'is closely held by the base fabricdue to the stitching can Yfreely run underneath the. movable blade, no

stretching effect being produced on said fabric. Due to-thisarrangement, the cutting device maybe seteXtremely-close to the needle, and this -is an advantage because themargin aroundthe stitch should be as narrow as possible. y W.

The lower or stationary blade` which is preferably verynarrow so as not .tounduly stretch the cloth, is preferably made detachable from the stem, so that a new blade' may be quickly insertedin position when the old blade isworn out.

Close adherence of the movable tothe sta-v tionary .blade is obtained by means of a spring 34, the action of which is such as to force the movable blade outwardly,-` against the stationaryblade. Said spring is made of a piece of steel wire which is permanently attached atone end to member 28, by means 'of a` screw l In the device described'in myapplication N o. 89,465,I have pointed out the advantage of bending to one side the'outer Aend ofthe stationary blade as shown at 37 in'Fig. 9; this bend being providedgin order to afford an eicientsupport for the fabric to be cut by Ythe device, so as,y to assist the feeding action of the presser foot. v

This'transversal tract alsofacilitates the shows, and the fabricmust then bedisengage from the blade Lbefore the? work can be proceeded with. V l

bending!V the free end vwork in thatit positively prevents the possibility of the blade sliding out of position from underneaththe fabricyit alsoA assists in maintaining the fabric tobe cut at right angle to the cutting edges so that a Lsharp cuttingaction is obtained thereby. By 'shifting the movable blade to the inner position, it becomes .advantageous Ato kinsure s a condition where itsouter vend doesfn'otreach the stationary or lower blade evenjwlien the 'movable blade is at the eXtreme end of its downward travel,as'shown in Fig. 4;,'this making itpossible to connect thealower end of connection 32 to the outer face offthelmovyable blade by means of: a pivot 38, 'witho'ut the possibilityof interference by the lower or stationary blade.' f

However, in operating this typeof blade',I`

have found that its laterally bent end portion frequently interferes with the progress of the work when an*l openmesh fabricis usedfor producing the work. yThis interference Awith the progressof the worklis likely to -occur when the trimming device is angularly moved sign; more particularly some difficulty islike- Y ly to ariseYwhenthetrimmingdevice is turned in t-he direction ,of the bent portion of the l blade as indicated by. the .arrow in F ig.`9. movable blade abuts against the inner face of the stationary blade, so that'the inneripart In this case, the pointed end of the bent portion of the blade may easily penetrate between vthe meshesof the fabric,.-as the drawin Openmesh kfabrics such as shown, known as v nets, are very; frequently used in kthis class. of

work and thereforethe operationof thedevice is seriously hampered in such uses; I.l have therefore further improved ymy ldevice by I of the stationaryk blade laterally to form a transversal :tract 39-an`d theninwardly to form a longitudinal tract`40,

as shown invFigs. 71and8. "i

, In this manner any movement of thek ming-device transversely of thestitching line will 'causea longitudinaltract of blade to abut against the fabric du ringcthe movement f in eitherdirection, insteadl of ay point which mighteasily become .enmeshed in the open work ofthe fabric itself. The possibility of such' an occurrence is thus positively prevent-` ed, both if the trimming devicecisdisplaced towardsor away from the-direction .ofthe stitch line. z x

The samearrangement may,-of course,- be adopted wherethe trimming device andthe needle bar are not rotatable about .their v'common axis, but the fabric is' displaced instead according to the design to be produced; in this case also, a. continuous tract of blade i'sin the 'path of the fabricy instead of a point,l whether the fabric is fed longitudinally ofthe trimming line in the normal way or whether Vthe fabric is displaced transversely of the instead of being bent to form a transversal and a :longitudinal tract; provided the free end of the curve Vis-directed transversely to the possible direction of movement of the fabric, or to the direction of displacement of the cutting edges of the trimming device, when a bend in thetrimming is produced, and isfdirected away from the fabric when said fabric is .fed in a sti'aight line in a normal direction. Therefore, such a curved bend should be well extended inwardly so: as to prevent the possibility of tspointed end penetrating the Vmeshes ofz the fabric when `the fabricis not moved strictly inthe direction of the cutting `edges of the blades, but is rotated about the --cutting point of the trimming device as-a pivot, or when the 1vtrimming Vdevice itselfis `displaced'aroundits axis as previously described.

Thisl isequivalent to saying that the ex- `treme end of thestationary blade must be directed at an angle to and preferably inwardly of a line outwardly extending from said extreme end tangential to a circumference passing through said extreme end having for its center, the center of rotation of the cutting 'device or of the fabric as the casemay be.` The angle atwhich the extreme end of the blade is directed in relation tov said tangential line shouldbe fairlyv wide in order to effectively avoid the possibility ofsaid free end becoming entangled in the meshes of the fabric.

Itis possible, of course, that for the production of certain designs, the -fabric or the trimming device may have to be turned in one direction only; this is true for instance in the cutting'of a circular, or oval, or rectangular outline, wherethere'are no recesses inthe outline requiring occasionalturnings in the opposite direction. In this case, it is suilicient to bend the blade laterally only in one direction, which when the trimming device is to the right of the needle, is'the outward direction as shown at 4l, in Fig. l0 because if the fabric is the element which is displaced the same only has to be turned in a counter clockwise direction, and theffree end of the stationary blade 'being bent away from the fabric, that is, in

the directionY of the lateral feed of the fabric when turning, there is no danger of the point lpenetrating between themeshes, a continuous `fabrics of all kinds and weaves,including open mesh fabrics, and'therefore, its efficiency and its field of application are considerably increased. Y I claim: f

1. Ina sewing machine7 :the combination with a needle bar capable of axiall reciprocat- Aing motion, of a trimming device co-acting therewith, comprisingfa stationary and a movable blade, said stationary blade havingl its free end bent reversely ofsaidblade so that if either the fabric or Vthe trimming" device is displaced oneiwayy or the other transversely of the direction of the stitch in order to change said direction, the'contact between the blade and fabric-is established througha continuous tract orfblade transversely to the directionof said displacement.

2. In a device of the class described, the

combination with a movable blade, of a staf tionary blade insertable underneath the fabric to be trimmed by said device, said stationary blade having its free end bent laterkally and reversely fof said `blade'in order-'to present a tract' directed transversely to theV direction of movement'wheneither thefabric or the trimming device is moved transversely to the direction of the stitch. 'i

3. In a device ofthe class described, the combination with a movable blade, of a stationary blade insertable underneath thev fabric to be trimmed by said device, said sta- 'tionaryblade having its 4free end bent laterally-to form` a transversal tract,` and then inwardly to form .a longitudinal tract substantially parallelto the device.' i

4f. In a machineof the character specified, the combination witha needle bar capable of cutting edge `of :the said axial reciprocating motionland capable of'aiii ming device is angularly displaced in either direction together with the needle bar about their common axis.

i 5; In a machine ofthe characterl specified,

'the combination with a needle bar capable of axial reciprocating motionand capable of angular movement about its own axis, and

an axially stationary member coaxial and adapted to rotate with said needle bar, of a trimming device having a movable blade operatively associated with said needle bar, and a stationary blade mounted on said member llO adapted t0 be inserted underneath the fabric to be trimmed by said device, said stationary lblade having its free Vend bent laterally to form a transversal tract and t-hen inwardly t0 form va longitudinal tract substantially parallel to the cutting edge ofsaid blade.

6. In a machine of the character specified, the combination with a needle bar capable of yaxial reciprocating motion and capable of angular movement about its own aXis, and an axlally stationary member coaxial and adapt` 1 stationary blade mounted on said member adapted to be inserted underneath the fabric to be trimmed by said device,-said stationary blade having its free end bent laterally andy inwardly of said blade and being directed inwardly of a line outwardly extending from 20 said end, tangentially of its path of travel.

y ANTONIO MISTRETTA. 

